You cannot mix an element with oxygen to make fire. Fire is a chemical reaction that occurs when a fuel (such as wood, paper, or gasoline) reacts with oxygen. The element that is mixed with oxygen to make fire is not an element, but rather a compound called a hydrocarbon. Hydrocarbons are molecules that contain carbon and hydrogen atoms bonded together. When hydrocarbons are burned, they react with oxygen to produce carbon dioxide and water vapor, releasing energy in the form of heat and light.